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<title>Amplify / AmplifydB Avisynth Filter</title>
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<h2>Amplify / AmpiflydB</h2>
<p><code>Amplify </code>(<var>clip, float amount1 [, ...]</var>)<br>
  <code>AmplifydB </code>(<var>clip, float amount1 [, ...]</var>)</p>
<p><code>Amplify</code> multiplies the audio samples by <var>amount</var>. You can specify 
  different factors for each channel.<br>
  If there are more volumes than there are channels, they are ignored. If there 
  are fewer volumes than channels, the last volume is applied to the rest of the 
  channels.
</p>
<p> <code>AmplifydB</code> is the same except values are in decibels (dB).<br>
  You can use negative dB values (or scale factor between 0 and 1) for reducing 
  volume. Negative scale factors will shift the phase by 180 degrees (i.e. invert the samples). </p>
<p>8bit and 24bit Audio samples are converted to float in the process, the other audio formats are kept.
<pre># Amplifies left channel with 3 dB (adds 3 dB): 
video = AviSource(&quot;c:\filename.avi&quot;) 
stereo = WavSource(&quot;c:\audio.wav&quot;) 
stereo_amp = AmplifydB(stereo, 3, 0) 
return AudioDub(video, stereo_amp) </pre><br>
      <pre># Amplifies front channels with 3 dB (adds 3 dB): 
video = AviSource(&quot;c:\divx_6ch_wav.avi&quot;) 
audio = WavSource(c:\divx_6ch_wav.avi) 
multichannel_amp = AmplifydB(audio, 3, 3, 3) 
return AudioDub(video, multichannel_amp) </pre>
<p>How the multichannels are mapped can be found in the description of <a href="getchannel.htm">GetChannel</a>. 
<p><kbd>$Date: 2009/09/12 15:10:22 $</kbd>

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